Anisotropic conduction, oxides

Aluminum oxide, as stabilizer, 296 Anderson model of superconductivity, 2 Anisotropic conduction, oxides, 40 Anisotropic GL theory, to ana superconductors. 19 Ann type, effect on cell parameters and magnetic properties, 142 Annealing parameters, films, 238,24(y Applications, BCS theory of superconductivity, 114 Argon laser-etched patterns, thin films, 257-25Atomic structure LajCuO, 27,2, 29 orthorhombic Y-Ba-Oi-0,27,2 ... 

The interest in the optical properties of the tetracyanoplatinate compounds has increased rapidly since the detection of the highly anisotropic conductivity of the partially oxidized systems5 12). In the meantime it has been proved that also the non-partially oxidized tetracyanoplatinates(II) exhibit fascinating features, mainly in the optical field. 

Control of macroscopic orientation of the microphase-segregated structures leads to efficient anisotropic conduction of proton and ions [132-139], Proton conductive supramolecular materials have been prepared by using microphase segregation of supramolecular block polymers 42 consisting of poly(styrene)- tock-(4-vinylpyridine), toluene sulfonic acid, and 3-pentadecyl phenol (Figure 31) [137]. Ionic conductive side-chain polymers have been obtained by complexation of oligo(ethylene oxide)sulfonic acid with poIy(styrene)-fe/ock-(4-vinylpyridine) [139]. 

Aiming at the CSP application market, Merix Corporation and Auburn University collaborated to develop anisotropic conductive adhesives called Area Bonding Conductive (ABC) adhesives. ABC adhesives are two-region thermoset adhesives with electrically conductive adhesive pads surrounded by a continuous oxide-filled dielectrical adhesive to form a total area bond. Both regions are solvent-free, B-staged, nontacky epoxies supplied on a Mylar carrier release film. In contrast to conventional ACAs, conductive areas of ABC adhesives are located only at bond pad locations. The assembly process for using ABC adhesives is shown in Fig. 9. The ABC adhesives... 

The use of both nonconductive epoxy adhesives and anisotropic conductive adhesives as a solder replacement for SMT was studied [121]. Quad flat pack components were connected to FR4 substrates and then subjected to temperature cycling. None of the tested adhesives passed the temperature cycling test in accordance with the military standard 883C [121]. Failure analysis indicated that impressions made in the contact area depend on the contact force and surface preparation. At very low contact forces, the presence of insulating oxide layers on the metal surfaces increased the contact resistance dramatically. However, as the contact force was increased, the contact resistance dropped rapidly [122]. 

Both the oxides (3- and (3"-alumina show extremely high Na+ ion conductivity. As the structure suggests, the conductivity is anisotropic, and rapid sodium ion transport is limited to the two-dimensional conduction plane. There is almost unimpeded motion in the Na+ layers, especially in (3"-alumina, which lacks interstitial oxygen ion defects in the conduction plane, and the conductivity is of the same order of magnitude as in a strong solution of a sodium salt in water. The conductivity is a... 

The salt may be best described as a mixed-valence compound containing platinum in the 2.3+ oxidation state. The combination of the mixed-valence state, the very short Pt— Pt separation of 2.89 A (only approximately 0.1 A longer than in platinum metal), and the formation of linear Pt—Pt chains along the c axis gives rise to the high, anisotropic metallic conductivity in this material.1... 

Dioximes form bis complexes (35) where the ligand normally chelates through the nitrogen atoms.251-253 Detailed studies have been made of the partially oxidized compounds obtained from reaction of bis(diphenylglyoximato)- and bis(benzoquinone dioximato)-palladium with iodine254,255 and bromine.256 These complexes contain polyhalide anions and possess the high anisotropic electrical conductivity associated with many complexes which crystallize as stacked molecular units.257... 

The 2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO) was first prepared in 1960 by Lebedev and Kazarnovskii by oxidation of its piperidine precursor.18 The steric hindrance of the NO bond in TEMPO makes it a highly stable radical species, resistant to air and moisture. Paramagnetic TEMPO radicals can be employed as powerful spin probes for elucidating the structure and dynamics of both synthetic and biopolymers (e.g., proteins and DNA) by ESR spectroscopy.19 Unlike solid-phase 1H-NMR where magic angle spinning is required in order to reduce the anisotropic effects in the solid-phase environment, solid-phase ESR spectroscopy can be conducted without specialized equipment. Thus, we conducted comparative ESR studies of various polymers with persistent radical labels, and we also determined rotational correlation times as a function of... 

A (100) silicon wafer 10 is anisotropically etched to form hollows 11 having sloped sides 15. A plurality of via holes are etched or laser drilled through the floor 17 of each hollow. Next, the wafer is oxidized to coat its surfaces with a first insulator of SiC>2. A refractory conductor is deposited within the vias to form conductive conduits. A perspective view of a single hollow is shown below. 

The compounds differ in their Pt—Pt intrachain separations, electrical conductivities, degree of partial oxidation of the platinum atom, and metallic color. These major differences occur even though two pairs of these four compounds contain the same anion, (FHF)-, and cation, Rb+ or Cs+. This provides the unique opportunity to explore only the effects of structural, not elemental, changes on the anisotropic electrical behavior of POTCP salts. 

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